Rim latch



A. ZION RIM LATCH' Dec. 30, 1941.

Filed Aug. 3, 1939 Patented Dec. 30, 1941 UNITED STATES PATENT OFFICE RIM LATCH Alfred Zion, Montreal, Quebec, Canada Application August 3, 1939, Serial No. 288,111

(Cl. l-151) 9 Claims.

This invention relates generally to rim locks and more particularly to night latches in which the bolt may be latch locked, that is, held in a retracted position, and may also be dead locked, that is, held in a protruded position, so that the latch cannot be opened by pushing .the bolt inward.

It is the general object of my invention to provide a latch of the type described that is simple in construction, effective in operation and low in manufacturing cost.

In spring latches of conventional types it is customary to have a control knob or button to effect the latch locking and the dead locking,

while retraction of the bolt is effected by anbe and is intended to be effected automatical- 1y when the protruded bolt, as the door is shut, is pushed inward by the strike plate. After being pushed inward the bolt moves outward into the recess in the strike plate and the dead locking is thereby elected.

While rim latches in which the dead latching is effected automatically are not unknown, in all of the types with which I am familiar, mechanism additional to the retractor mechanism is used. It is therefore further among the objects of my invention to provide a rim latch in which the bolt retractor mechanism, besides effective retraction of the bolt is also adapted to effect automatic dead locking of the bolt.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, I make reference to the accompanying drawing, forming a part hereof in which:

Figure 1 is a bottom plan view of my improved latch with the cover plate removed and showing the retractor pin and the bolt in the latch locking position, with the bolt retracted;

Figure 2 is a view similar tov Figure l, but showing the bolt in a partly protruded position and the retractor pin in a different position;

Figure 3 is a view similar to Figure 1 showing a portion of the latch with the retractor pinin a position intermediate that of Figures 1 and 2;

Figure 4 is a view similar to Figure 1 showing the latch bolt and retractor pin in their dead locking position;

Figure 5 is a longitudinal sectional view substantially on the line 5-5 of Figure 4 looking in the direction of the arrows;

Figure 6 is a transverse sectional view substantially on the line 6-6 of Figure 4;

Figure 7 is a view of the inner side of the cover plate of the latch, showing the key retractor.

Referring to the drawing in detail, I0 therein designates the hollow casing of the lock which casing comprises a top wall II, side walls I2 and I3, and end walls I4 and I5. Ribs or lugs I6, I1, I8, I9, 20 and 2I serve to provide seats for rim portions of a cover plate 22 which may be secured to the casing in any suitable or preferred manner, such as by screws 23 that thread into posts 24 extending from the inner side of the top wall II.

Suitable openings 25, 26 and 2l are shown through which screws or other fastening means may pass, by means of which the latch may be fastened to a door. It will be understood that corresponding openings or cut-away portions permitting the passage of such fastenings are provided in the cover 22. At 28, for instance, is shown a slot in the cover 22 through which, and through the opening 21 in the casing there may pass a screw 29, shown in dot and dash lines (see Figure 5).

Mounted for sliding movement in the casing is a bolt 30 provided with a head 3l having a flat outer face 32, adapted to abut the shoulder of a strike plate S (shown in dot and dash lines), and an inclined face 33 adapted to engage the strike plate S and to cause inward movement of the bolt when it does so.

The bolt 30 further comprises a stem or shank portion 34 which is shown in the form of an elongated member having a central cut-out portion along the middle of which extends in a longitudinal direction a dead-locking pin 35. As a matter of practical manufacturing the shank portion 34 may be in the form of a sheet metal stamping, one end of which, 36, may conveniently extend into a groove in the head 3|, to which it is then fastened in any suitable or preferred manner, as for example, by riveting (not shown).

The head portion 3I of the bolt is slidable in an opening 31 in the end wall I4 of the casing, while the shank portion 34 is slidably supported and guided by a system of supports and guides of which the lateral guides 38 and 39 may be mentioned. The guides in the casing I0 are so arranged, however, that the bolt may be lifted off its supports while at the same time the head 3| thereof is slid out of the opening 31 and thereby its removal from the casing effected. In order to maintain the bolt in its seat, the cover plate 22 may be provided with a pair of lugs 38a and 39a (which may be struck up therefrom) and which slidably engage the outer surface of the bolt shank 34.

The dead locking pin is also guided on the combined support and guide 49 Within a groove in which it slides and this guide at the same time serves as an abutment for one end of the bolt spring 4| which is adapted to project the bolt 30 out of the casing i9. A washer 42 may with advantage be interposed between the spring and the guide 49. The other end of the spring 4| is shown as abutting against the bolt head 3|.

The edges of the opening 43 in the bolt shank 34 are provided on one side thereof With concave cam surfaces 44 and 45 in adjacency to each other and so dimensioned and contoured that they will cooperate with a retractor pin 46 in the manner to be described hereinafter.

A set of cam surfaces 4l and 48 similar to the surfaces 44 and 45 are symmetrically positioned on the opposite side of the opening 43. By reason of this construction and by reason of the positioning of the bolt shank 34 centrally ofthe bolt head 3|, the bolt is reversible, so that it can be used for either outwardly or inwardly opening doors by simply changing the position of the bolt to the position required. Y

Journalled within the top plate is the retractor knob 49 which carries eccentrically mounted thereon the aforementioned retractor pin 49. A stop U carried by the top plate limits the position of the pin in one direction and a spiral spring 5| anchored at one end to the stop 59 and at its other end to some part associated with the knob 49, serves to urge the knob so that the pin 46 moves against the stop 5|).

The pin 46 extends through the opening 43 of the bolt shank 34 and a suicient distance below the same to intersect the path of a pair of retractor arms 52 that are carried by a member 53 journalled in the cover plate 22, which is provided with a slot 54 adapted to receive the connector bar 55 of a lock cylinder 56, shown in dot and dash lines in Figure 5. Obviously connection of the member 53 to any other desired type of lock may also be readily effected.

It will be observed therefore that the pin 46 may be controlled either manually through the knob 49 or through the key-operated member l53.

The operation of my improved lock will now be described.

We Will assume rst of all that the retractor pin 46 is in the position of Figure 4 which is one limiting position, with the pin against stop 50, and that the knob 49 is turned clockwise, as seen in that figure. Urged by the spring 4| the bolt 30 always tends to move to the left as far as it is permitted by pin 49, which resists such movement by its contact with the walls of the opening 43.

As the knob is turned, the pin 45 rst seats itself within the cam surface 45, as shown in Figure 2, and this position, in which the bolt is slightly retracted, is found to be a position of stability from which the pin can be displaced by turning the knob 49 in a clockwise direction. If it is attempted to turn the knob 49 in a counter-clockwise direction as viewed in Fig. 2, however, it is found that thiscannot be done, be-

cause the surface 45 is contoured so that the portion 51, which can only move to the left or the right, extends across the circular path of pin 46.

If the clockwise movement of the knob 49 continues, the pin 4B rides along the edge of the opening 43 from the cam surface 45 to the cam surface 44, retracting the bolt shank 34 as it does so. After the pin 45 has reached its uppermost position it commences to move down on the right side of the axis of knob 49 until it reaches the beginning of the cam surface 45, as shown in Figure 3, at 45a, and in this position the bolt is completely retracted, so that the door may be opened.

If the knob 49 be now released the bolt will move outward a slight distance, and the pin 49 and the other parts will assume the stable position of Figure 2. If however the turning of the knob 49 is continued in a clockwise direction the pin 46 will move into the cam surface 45 and assume the stable position of Figure 1, in which the bolt is completely retracted. This position may be referred to as the latch lock position and further turning of the knob 49 clockwise will be found to be impossible.

If now the knob 49 be turned counter-clockwise from the position of Figure l, the next of the illustrated positions to be reached will be that of Figure 3 after whichthe spring 4| urges the bolt and the knob 49, which is additionally urged by spring 5| into the position of Figure 2, which again is a limiting position beyond which the knob 49 cannot be turned counter-clockwise.

If now however the bolt 30 be pushed inward, as by engagement of the inclined surface 33 thereof with the strike plate, the inwardl movement of the bolt shank releases the pin 46 from its seat in the cam surface 45, rst striking the upper surface of the dead locking pin 35, as shown in Fig. 2 in dotted lines. This restrains the movement of the retractor 46 in a counterclockwise direction, as so urged by the spring 5|. Upon projection of the bolt into the strike plate orifice in the position shown in Fig. 4, the pin 48, as it is released by the pin 35 is urged into contact withstop 59 by the spiral Yspring 5| and moves directly into the path of the dead locking pin 35, as shown in Figure 4, whenl the bolt 3| has been spring projected.

It will be observed that inward movement of the bolt will in all cases release the pin 46 and cause it to move into the dead locking position. It is further to be observed that the automatic dead locking action by contact of the bolt with vthe srike plate can only take place when the bolt is suilciently protruded to engage the strike plate.

Assuming now that the lock is installed on a door and that a person inside the room wishes to leave it and to leave the rim latch in its dead locked position, he will grasp the knob 49, which is on the inside of the room, and retract the bolt until the position of Figure 3 is reached, at which point, the bolt is retracted, and the person will then open the door and release the knob 49, which has the effect of causing the parts to assume the position of Figure 2, with the bolt protruded. He then steps out and shuts the door, and as he does so the contact of the, bolt with the strike plate results ultimately in positioning the bolt in the recess of the strike plate with the bolt dead locked as shown in Figure 4, the pin 45 being positioned in the dead center in line with the shank 35.

Alternatively, before opening the door, the knob 49 may be turned to its limiting position of Figure 1 so as to latch lock it and after the door is opened, a slight movement of the knob in the reverse direction will move the pin 46 into or be- 1 yond the position of Figure 3, after which the knob is released, as before. This procedure is perhaps preferable to the preceding one since the operator is always sure that the bolt is released, whereas when he does not turn the knob 49 in the reverse direction (as in said preceding procedure) there is a chance that the knob may have been turned too far, so that the position of Figure3 is passed, and the parts may be in the position of Figure 1, so that the desired release of the bolt and dead locking will not take place.

In order to prevent this contingency a spring detent or the like may of course be provided, which will clearly indicate to the operator when the position of Figure 3 is reached, without however preventing movement of the pin 4E into the position of Figure 1.

With the latch parts as positioned in Fig. 1 outside buttons to hold the bolt in the fully retracted position need not be provided and my construction effects substantial economies by reason thereof.

With the latch in its dead locking position of Fig. 4, it is of course impossible to open the lock by pushing in the bolt, as would be the case in attempting to tamper with the lock by inserting a knife blade in the slot between the strike plate S and the lock.

When the room is to be entered from the outside the latch bolt is manipulated by a suitable key acting on the latch bolt through the retractor mechanism 52, 53 and 46 already described. Manipulation of the latch bolt by means of the -key is entirely similar to manipulation thereof by the knob 49 as will be obvious and consequently need not be repeated.

It will therefore be seen that I have provided a rim lock of simple and effective construction and of low manufacturing cost, in which the operations of retracting the bolt, of latch locking the bolt or of dead locking the bolt may be effected by simple manipulation of a single control.

It will be understood of course that the various features of my invention need not necessarily be used conjointly and in the combinations shown, but that they may be used in other relations and in other combinations.

It is further to be understood that while I have herein shown and described one illustrative embodiment of my invention, that the same may be embodied in many other forms without departing from the spirit thereof, as will be obvious to those skilled in the art, and that the disclosure herein is by Way of illustration merely and is not to be interpreted in a limiting sense, and that I do not limit myself other` than as called for by the appended claims.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. In a rim lock a bolt provided with a shank, means for urging said bolt into a protruded position, a retractor, a pivotal mounting for said retractor, a pin eccentrically carried by said retractor, a set of cam surfaces on said shank so contoured and positioned that they will be engaged by said pin when said retractor is turned and will move the bolt against the action of said bolt urging means, and means for urging said retractor into a normal position and a deadlocking pin which extends into the path of said retractor pin, serving to restrain the movement of said retractor pin in one position and dead locking the latch bolt by engaging said retractor pin in another position.

2. In a rim lock a bolt provided with a shank, means for urging said bolt into a protruded position, a retractor, a pivotal mounting for said retractor, a pin eccentrically carried by said retractor, a set of cam surfaces on said shank so contoured and positioned that they will be engaged by said pin when said retractor is turned and will move the bolt against the action of said bolt urging means, and means for urging said retractor into a normal position, said last named means comprising a spring adapted to cause rotation of the retractor and a stop to limit such rotation comprising a dead locking pin carried by said shank, serving to restrain the movement of said retractor pin in one position and engaging said retractor pin to dead lock the latch bolt in another position.

3. In a rim lock, a bolt provided with a head and with a flat shank, an opening in said shank, means for urging said bolt into a protruded position, a pivotally mounted retractor, means for urging said retractor into a limiting position, a pin eccentrically mounted on said retractor, a

plurality of concavely contoured cam surfaces on the end edge portions of said opening to one side of the median line of the bolt adapted to receive said pin, a dead locking pin in said opening having its free end pointing away from said head, and said limiting position of said retractor pin being in the path of the end of said dead locking pin, whereby retraction of said bolt will be prevented when said retractor pin is in its limiting position, and said cam surfaces being so contoured that the retractor pin may assume a position in which it dead locks the bolt, and that when said bolt is pushed inward, said retractor will be released and the retractor pin` will automatically move into its dead locking position.

4. In a rim lock, a bolt provided with a head and with a fiat shank, an opening in said shank, a pivotally mounted retractor, means for urging said retractor into a limiting position, a pin eccentrically mounted on said retractor, a plurality of concavely contoured cam surfaces on the end edge portions of said opening to one side of.

the median line of the bolt adapted to receive said pin, a dead locking pin in said opening having its free end pointing away from said head, a coil spring for urging said bolt into a protruded position mounted on said dead locking pin, and upon movement into a protruded position of said bolt and the limiting position of said retractor, said eccentric pin being in the path of the end of said dead locking pin, whereby retraction of said bolt will be prevented when said retractor pin is in its limiting position, and said cam surfaces being so contoured that the retractor pin may assume a position in which it dead locks the bolt, and that when said bolt is pushed inward, said retractor will be released and the retractor pin will automatically move into its dead locking position in alignment With said dead locking pin.

5. In a rim lock, a single beveled bolt provided with a shank portion having sets o symmetrically positioned cam surfaces, and an axially positioned dead locking pin serving as a bolt projector spring guide so that the bolt can be reversed and one set of said cam surfaces will,

in either position of the bolt, be operatively posi- 'tioned, and retractor means carrying a retractor pin adapted to engage the operatively positioned cam surfaces in reverse or obverse position of said bolt.

6. A rim lock provided with a single beveled bolt having a flat shank portion having an axially extended dead locking pin serving as a bolt projector spring guide, an opening in said shank portion, a pair of cam surfaces on the edge of said opening, said cam surfaces being symmetrically disposed about the longitudinal axis of the bolt and said dead locking pin so as to permit of its reversal.

7. A rim lock comprising a bolt, means for urging said bolt into its projected position, a retractor, means for urging said retractor into a limiting position and complementary means on said bolt `and said retractor comprising an extension pin on said bolt and a retractor pin on said retractor, whereby when said bolt is pushed inward and then released, said retractor will automatically dead-lock the bolt in a protruded position by engagement of said retractor pin with said extension pin in the aligned position oi said retractor pin and extension pin.

8. In a rim lock of the character described, a pivotally mounted retractor having a retractor pin, stop means carried by the bolt of said lock,

rtion of said bolt.

9. In a rim lock mechanism, the combination which comprises a spring projected latch bolt, a shank therefor to be engaged by a retractor and having a dead locking portion carried thereby, a retractor having a pin engaging said shank, said retractor carrying said pin having means normally to urge the pin thereof into a dead locking position and means carried by said shank of said latch bolt to hold said retractor pin in a position displaced from the dead locking position upon manual retraction of said latch bolt, said means so carried by said shank of said latch bolt being formed to release said retractor pin when the latch bolt is externally depressed to permit said first means to urge the pin into a dead locking position by aligning said pin in the path of Said dead locking portion of said shank when the latch bolt is projected into the orifice of the strike plate.

ALFRED ZION. 

